The investigation into the disappearance of Malaysia Airlines Flight 370 shifted Saturday to the passengers and crew after data showed the plane deviated from its flight plan due to what appears to be deliberate action, Prime Minister Najib Razak said Saturday.

“Malaysian authorities have refocused their investigation on crew and passengers aboard,” Najib told reporters. “Evidence is consistent with someone acting deliberately from inside the plane.”

Najib stopped short of calling it a hijacking, saying investigators have not made a final determination.

“Despite media reports that the plane was hijacked, we are investigating all major possibilities on what caused MH370 to deviate,” he said.

Shortly after he spoke, a source close to the investigation told CNN that Malaysian police had searched the home of pilot Zaharie Ahmad Shah, 53. Shah lives in a gated community in Shah Alam, outside Kuala Lumpur.

Earlier Saturday there was no police presence at the residence of his co-pilot, Fariq Ab Hamid, 27.

Kazakhstan to Indian Ocean

As the focus of the investigation has shifted, so too has the focus of the search. “The plane’s last communication with the satellite was in one of two possible corridors: a northern corridor stretching approximately from the border of Kazakhstan and Turkmenistan to northern Thailand, or a southern corridor stretching approximately from Indonesia to the southern Indian Ocean,” Najib said.

Given that the new search area involves a number of countries, the relevant foreign embassies have been given access to the new information. Malaysia’s Foreign Ministry will brief the governments that had passengers aboard the plane and will brief the relatives of its 239 passengers and crew.

The passenger jetliner disappeared on March 8, en route from Kuala Lumpur to Beijing.

“Based on new satellite information, we can say with a high degree of certainty that the Aircraft Communications Addressing and Reporting System, or ACARS, was disabled just before the aircraft reached the East Coast of peninsular Malaysia,” the Prime Minister said. “Shortly afterward, near the border between Malaysian and Vietnamese air traffic control, the aircraft’s transponder was switched off. From this point onwards, the Royal Malaysian Air Force primary radar showed that an aircraft — which was believed but not confirmed to be MH370 — did turn back.”